The current scientific consensus is that the universe is approximately 13.8 billion years old. This estimate is based on a variety of observational data and theoretical models, including measurements of the cosmic microwave background radiation, the rate of expansion of the universe, and the observed distribution and age of galaxies.
The age of the universe is derived from the concept of the Big Bang, a model that suggests the universe originated from a highly dense and hot state approximately 13.8 billion years ago. This model is supported by numerous lines of evidence, including the observed redshift of distant galaxies and the abundance of light elements in the universe.
It is worth noting that scientific understanding and estimates of the age of the universe have evolved over time as new data and observations become available. However, the 13.8 billion-year figure represents the most widely accepted estimate based on current knowledge and measurements.